What is Dorothy thankful for at the end of her journey?

Dorothy is happy to have achieved her greatest wish..... to return to her Aunt and Uncle in Kansas.

The value of the journey

Dorothy's route back to Kansas is not simple. Even though there was a simple solution from the beginning - the silver shoes - she did not know about it and profited far more from the lengthier, more dangerous journey it took to get back to Kansas. This journey provided her with several life lessons. She learned the value of friendship through her three traveling companions. She came face-to-face with the reality of duplicity and lies through the Wizard's shocking reveal as an ordinary man. She saw the fight between Good and Evil play out through the Witches. She found herself tested emotionally and physically. And, finally, she learned to trust herself and that the answers to her problems lie within her. She benefited from the company of others but the solution of how to get back to Kansas could be found within all along. This journey, then, gave her much more insight into herself and taught her how to navigate an oftentimes treacherous and confusing adult world.